AP BIOLOGY

Detailed explanation-1: -A tumor suppressor gene encodes a protein that acts to regulate cell division, keeping it in check. When a tumor suppressor gene is inactivated by a mutation, the protein it encodes is not produced or does not function properly, and as a result, uncontrolled cell division may occur.

Detailed explanation-2: -Mutations in genes can cause cancer by accelerating cell division rates or inhibiting normal controls on the system, such as cell cycle arrest or programmed cell death. As a mass of cancerous cells grows, it can develop into a tumor.

Detailed explanation-3: -A type of gene that regulates cell growth. When a tumor suppressor gene is mutated, uncontrolled cell growth may occur. This may contribute to the development of cancer.

Detailed explanation-4: -Examples of tumor suppressor genes are the BRCA1/BRCA2 genes, otherwise known as the “breast cancer genes.” People who have a mutation in one of these genes have an increased risk of developing breast cancer (among other cancers).